IKONOS, High resolution Imagery Evaluation
Jedsada Kerdsrilek
Geo-Informatics and Space Technology Development Agency (GISTDA),
Bangkok, Thailand
Tel: (66)-2-326-4284 Fax: (66)-2-3264291
Email: jedsada@gistda.or.th
Abstract:
This paper reports the evaluation results of several IKONOS product ,using a study area in Chiang
Mai Province. Sixty check points were utilized in the study area and network differential GPS
technique was applied. The root mean square error and circular error 90 were performed for the
check points that passed the regulations.
1. Introduction
Satellite data especially high resolution imagery such as the imagery from IKONOS is considered
to have significant value these days. This is due to its high qualities, as the imagery can be timely
acquired and the satellite’s imaging system has multi-spectral band, This high resolution imagery is
applied in many aspects such as surveying , urban planning and most extensively in mapping.
However before such applications are used we need to know if the selected imagery has enough
accuracy and suits our requirement as each work requires imagery at different level of accuracy.
Therefore the important process before analyzing or using the imagery is to evaluate its accuracy. In
the processing of the high-resolution IKONOS imagery, Space Imaging Southeast Asia evaluates
the accuracy of the following product:
Geo Product , Standard Ortho, Reference Ortho, Precision Ortho and Precision + Ortho.
This research intended to study the positioning accuracy of each IKONOS imagery product, to
ensure that the product was used for the right objective. This project has received co-operation
from mapping government organizations and universities such as RTSD , DPT , DOL , Chula ,
POSU and KMUTT
The Accuracy Evaluation Process is explained on Flow Chart # 1, showing how study area images
and high precision check points were obtained. After that we made a measurement of error distance
on using the check points. We calculated root mean square error and circular error 90 and the
results were kept to apply and use in appropriate aspects .
Flow chart # 1 IKONOS imagery evaluation process using checkpoints
